crypto: algif_hash - Only export and import on sockets with data

The hash_accept call fails to work on sockets that have not received any data. For some algorithm implementations it may cause crashes. This patch fixes this by ensuring that we only export and import on sockets that have received data. Cc: [email protected] Reported-by: Harsh Jain <[email protected]> Signed-off-by: Herbert Xu <[email protected]> Tested-by: Stephan Mueller <[email protected]>
chewitt · Nov 2, 2015 · 4afa5f9 · 4afa5f9
1 parent 271817a
commit 4afa5f9
Showing 1 changed file with 10 additions and 2 deletions.
diff --git a/crypto/algif_hash.c b/crypto/algif_hash.c
@@ -181,9 +181,14 @@ static int hash_accept(struct socket *sock, struct socket *newsock, int flags)
 	struct sock *sk2;
 	struct alg_sock *ask2;
 	struct hash_ctx *ctx2;
+	bool more;
 	int err;
 
-	err = crypto_ahash_export(req, state);
+	lock_sock(sk);
+	more = ctx->more;
+	err = more ? crypto_ahash_export(req, state) : 0;
+	release_sock(sk);
+
 	if (err)
 		return err;
 
@@ -194,7 +199,10 @@ static int hash_accept(struct socket *sock, struct socket *newsock, int flags)
 	sk2 = newsock->sk;
 	ask2 = alg_sk(sk2);
 	ctx2 = ask2->private;
-	ctx2->more = 1;
+	ctx2->more = more;
+
+	if (!more)
+		return err;
 
 	err = crypto_ahash_import(&ctx2->req, state);
 	if (err) {